# ETL We are going to do the `Transform` step of an Extract-Transform-Load. ### ETL Extract-Transform-Load (ETL) is a fancy way of saying, "We have some crufty, legacy data over in this system, and now we need it in this shiny new system over here, so we're going to migrate this." (Typically, this is followed by, "We're only going to need to run this once." That's then typically followed by much forehead slapping and moaning about how stupid we could possibly be.) ### The goal We're going to extract some scrabble scores from a legacy system. The old system stored a list of letters per score: - 1 point: "A", "E", "I", "O", "U", "L", "N", "R", "S", "T", - 2 points: "D", "G", - 3 points: "B", "C", "M", "P", - 4 points: "F", "H", "V", "W", "Y", - 5 points: "K", - 8 points: "J", "X", - 10 points: "Q", "Z", The shiny new scrabble system instead stores the score per letter, which makes it much faster and easier to calculate the score for a word. It also stores the letters in lower-case regardless of the case of the input letters: - "a" is worth 1 point. - "b" is worth 3 points. - "c" is worth 3 points. - "d" is worth 2 points. - Etc. Your mission, should you choose to accept it, is to transform the legacy data format to the shiny new format. ### Notes A final note about scoring, Scrabble is played around the world in a variety of languages, each with its own unique scoring table. For example, an "E" is scored at 2 in the Māori-language version of the game while being scored at 4 in the Hawaiian-language version. ## Getting Started For installation and learning resources, refer to the [exercism help page](http://exercism.io/languages/haskell). ## Running the tests To run the test suite, execute the following command: ```bash stack test ``` #### If you get an error message like this... ``` No .cabal file found in directory ``` You are probably running an old stack version and need to upgrade it. #### Otherwise, if you get an error message like this... ``` No compiler found, expected minor version match with... Try running "stack setup" to install the correct GHC... ``` Just do as it says and it will download and install the correct compiler version: ```bash stack setup ``` ## Running *GHCi* If you want to play with your solution in GHCi, just run the command: ```bash stack ghci ``` ## Feedback, Issues, Pull Requests The [exercism/haskell](https://github.com/exercism/haskell) repository on GitHub is the home for all of the Haskell exercises. If you have feedback about an exercise, or want to help implementing a new one, head over there and create an issue. We'll do our best to help you! ## Source The Jumpstart Lab team [http://jumpstartlab.com](http://jumpstartlab.com) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.